1. Field of the Invention
This invention relates to network communication, and in particular, relates to a method and apparatus for reducing inter-wireless networks spectrum interference.
2. Description of the Related Art
The following description is a background introduction of the invention for assisting in a better understanding of the invention. However, it should be noted that it is not a confirmation that all contents presented in this part belong to the prior art. The content mentioned in this part may be prior art, but may also be technical content that is merely known to the inventor of the present patent application but does not constitute the prior art.
At present, network applications have already been popularized, and such widespread application is followed by network interference. In fact, the interference problem is almost everywhere, for example, inter-cell interference in cellular networks, interference from simultaneous transmission in ad-hoc networks, interference between adjacent networks in a wireless local area network, etc. As a rapid development of wireless network technologies and network applications, more and more network types and network applications are available for users to select. The result is that in practical applications, a plurality of heterogeneous wireless networks may co-exist in a specific area. One exemplary environment is, for example, Internet Of Things (IOT) applications. In addition, wireless networks such as WiFi (following the standards like IEEE802.11a/b/g or the like), Bluetooth, Wireless Sensor Networks (WSN) consisting of Zigbee, Wireless HART or the like, can work at the frequency band of 2.4 GHz ISM. Nevertheless, wireless networks of different types are normally different in network frameworks, communication standards followed or protocols, and their working frequencies may be identical, different or overlapping. For instance, channels 1, 6 and 11 in the IEEE802.11b North American channel selection (non-overlapping) standard respectively take 2412 MHz, 2437 MHz, and 2462 MHz as central frequency and occupy a bandwidth of 22 MHz; channels 1, 7 and 13 in the IEEE802.11b European channel selection (non-overlapping) standard respectively take 2412 MHz, 2442 MHz, and 2472 MHz as central frequency and occupy a bandwidth of 22 MHz; while channels 11-26 in the IEEE 802.15.4 channel selection (2400 MHz, physical layer) standard occupy a bandwidth of 2 MHz with a central frequency point every 5 MHz, from 2405 MHz to 2480 MHz. Thus, there may be overlapping among spectrum resources used in wireless networks following different communication protocols or standards, thereby generating an interference which will degrade the performance of the entire network.
However, the existing interference processing schemes are generally unsatisfying in their implementing process and effect. For example, static frequency allocation is widely used in cellular wireless communication systems such as GSM and CDMA, and mainly enables cells at a distance far enough from each other to uses an identical group of channels, which needs a dedicated network to realize the whole planning and lacks a certain degree of flexibility and expansibility. Furthermore, there is a multi-antenna technology in the existing solution, which may suppress interference signals by a proper multi-antenna airspace weighting at the receiving side with the orientation of the antenna when combining desired signals, but such a solution involves complex signal processing. Moreover, although the solution of energy detection which is widely used in networks like WiFi, WSN is relatively easy to implement, it is merely a detection against a fixed detecting point and a specific target point, and if, for example, the user deviates from the detecting point, it will be then unable to discover a potential/hidden interference for the user.
As can be seen from above, how to mitigate or even avoid the interference in wireless networks, especially the interference among heterogeneous wireless networks, is still an existing problem in network applications.